Apparatus for tuning stringed musical instruments



y 5 D. J. DICKERSON Q 2,514,315

APPARATUS FOR TUN'INGJSTRINGED MUSICAL INSTRUMENTS Filed July 11, 1949 NV EN TOR.

D51. Beer Jae/(5230 firTaQn/Ek Patented July 4, 1950 NITED STATESAPPARATUS- FOR TUNING STRINGED MUSICAL INSTRUMENTS Delbert .l'.Dickerson, Agoura, Calii-Z, assignor of one-halite Arthur B. McMahan,Long Beach,

Calif.

Application Ju y 11, 1949; Serial No. 104,060

2 Claims.

This invention relates generally to improved apparatus for tuningmusical instruments and partioul'arly'fiorztuning stringed instrumentssuch as guitars.

In employing any vibration responsive device for indicating when aparticular string of a mu sical instrument is correctly tuned, it isdesirable, for maximum effectiveness, to render the device as sensitiveas possible-to the string vibrations.

With this in mind, a major object of the present invention is to providehighly effective sound pick-up means by virtue of whi'Qh such vibrationsmay be transmitted or conducted from the strings of an instrumentdirectly to a tuning device with a minimum loss in intensity.

In instruments of the class with which we are here concerned, theplaying strings are usually supported at one end by a transverselyextending ridge or bridge. In accordance with the invention, I attainmaximum sensitivit in a sound pick-up device by employing novel means atthe location of this string carrying bridge for supporting the stringsresiliently and in a manner permitting appreciable vibration at thesupport locations. directly to the tuning device by the support itself.

Preferably, the strings are resiliently supported in the defined mannerby an insert receivable between the playing strings of the instrumentand the bridge. cushion of rubber or the like engageable with thebridge, together with a vibratable plate directly engaging the stringsand adapted to carry a vibration responsive tuning assembly.

The above and further features and. objects of th present invention willbe better understood from the following detailed description of thetypical embodiment illustrated in the accompanying drawing, in which:

Fig. 1 is a perspective view showing the present apparatus applied to aguitar;

Fig. 2 is a front elevational view of the removable tuning assembly;

Fig. 3 is an enlarged vertical section through the tuning assembly andtaken on line 3-3 of Fig. 2;

Fig. 4 is a perspective view of the reed unit in Fig. 2;

Fig. 5 is a plan view of the sound pickup device; and

Fig. 6 is a transverse section through the sound pickup device taken online B6 of Fig. 5.

Referring first to Fig. 1, I have illustrated the present tuningapparatus as applied to a guiter having a body I0 and carrying the usualplaying These vibrations are then transmitted This insert may include aresilient strings I I. These strings pass over a supporting ridgeOrbridge [2 for retention at one end by the usual tuning pegs l3. I

The tuning apparatus itself comp-risestwo sections, including a soundpickup insert to be carried between bridge 12 and'th'e playing strings,and a sound responsive tuning assembly lfi adapted to be removablycarriedby the insert duringa tuning operation. As best seenii-n Figs: 5and 6, the insert comprises an upper vibratable plate l? formed of metalor the like for most effective sound transmission and having on itsunder surface a rubber :cushionwfi for engaging the bridge toresiliently support the plate and strings. Plate H and cushion 26 aresecured together in any suitable manner, as by cementing. The plate isof trapezoidal configuration, having two parallel edges l8 and I9 andtwo converging edges and 2!. Along edge 18, the plate is curved firstupwardly and then downwardly to present a bead E2 to be received overthe edge of bridge l2 for locating the insert relative to the bridge.Along the upper surface of bead 22 the plate is grooved at spacedlocations 23 for receiving and locating strings I l. Near edge E9, theplate contains a pair of spaced openings 24 for receiving similarlyspaced pins 25 on the tuning assembl M5 to permit the tuning assembly tobe temporarily plugged in to the insert during a tuning operation.

The tuning assembly has a housing '27 with an angularly disposed sightopening 2-8 on its front side and having a removable back cover 29.Within this housing, I provide the reed unit illustrated in Fig. l,which comprises a clamp member 3i, attached depending pins 25, and anumber of reeds 32 each adapted to vibrate freely at a frequencycorresponding to the correctly tuned frequency of one of the strings H.Clamp member 3! is formed of a strip of sheet material doubled back uponitself to present two overlying portions 33 and 34 between which theends of the various reeds are clamped. Portion 3 3 of the clamp has apair of ears 35 at its ends provided with openings 36 for attachment tohousing 2'! by fasteners 31. Portion 34 of the clamp contains a seriesof spaced slots 38 dividihg it into a number of fingers 39 adapted toindividually retain the various reeds. Depending pins 25 are secured tothe clamp in any convenient manner.

In use, insert I5 is applied to the instrument between the bridge andstrings in the illustrated manner and remains in that position at alltimes. With the insert thus applied, cushion 26 serves to resilientlysupport plate I! and the strings in a manner permitting appreciablevibration of both the strings and the plate at the support locations.When it is desired to tune the instrument, the tuning assembly 16 isattached to the insert by reception of pins 25 within openings 24 topick up directly the vibrations of plate 11. When one of the strings I lis correctly tuned, the corresponding reed of the tuning assembly willvibrate freely as the string is plucked to serve as a visual indicationof correct tuning.

As will be understood, the plate I! tends to vibrate in accordance withthe vibrations of one of the plucked strings by virtue of the string andplate engagement at the bridge. The plate having a free edge I 9 assumesan oscillating vibration from its anchorage at the bridge, andconsequently may tend to amplify the vibrations as its dimension awayfrom the bridge increases.

Such vibration in turn is transmitted by the pins 25 to the housing 29and clamp 3|, to the reeds 32, and, since the vibration fulcrum is atthe bridge, in a manner such that as ultimately received by the reeds,the vibration transmission is angularly of the reeds. In this connectionit may be mentioned that the pins 25 and openings 24 may be made toaccommodate the tuning instrument at any desired angularity relation tothe plate 11. As shown, the body of the instrument is substantiallynormal to the plate.

I claim: 1. In a musical instrument having a plurality of stringspassing over a bridge, means on said bridge resiliently supporting thestrings and permitting appreciable vibration thereof at the supportlocations, said means including means adapted to vibrate with saidstrings, and a vibration responsive assembly connected to said lastmentioned means for indicating when a musical tone produced by one ofthe strings is a predetermined pitch.

2. For use with a musical instrument having a plurality of stringspassing over a bridge. an insert to be placed between said bridge andstrings and resiliently supporting the strings to permit appreciablevibration thereof at the support locations, said insert including meansadapted to vibrate with said strings, and a vibration responsiveassembly connected by said means for indicating when a musical toneproduced by one of the strings is a predetermined pitch.

DELBERT J. DICKERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,228,249 Alyn Jan. 14, 19412,487,192 Smith Nov. 8, 1949 FOREIGN PATENTS Number Country Date 205,560Germany Jan. 4, 1909

